


make me a promise

by SpaceMatriarchy



Category: Supernatural
Genre: Alternate Universe, Apocalypse, Episode: s15e09 The Trap, Hurt No Comfort, M/M, Ma'lak Box (Supernatural), Mark of Cain (Supernatural), Not technically MCD but MCfate worse than death
Language: English
Status: Completed
Published: 2020-04-18
Updated: 2020-04-18
Packaged: 2021-03-01 22:29:21
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 2,403
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23724616
Author URL: https://archiveofourown.org/users/SpaceMatriarchy/pseuds/SpaceMatriarchy
Summary: “Just make me a promise that when I can’t control myself, you’ll do it for me.”Set in Chuck's future AU from 15x09 - The Trap.
Relationships: Castiel/Dean Winchester
Comments: 7
Kudos: 52





	make me a promise

It was okay, for the first little while. 

Cas seemed on edge, maybe. Irritable, maybe. But he had always been a steady mind, with emotional fortitude, and everyone figured the effects of the mark would be reduced on an angel, if they presented at all. Cas didn’t have the chinks in his armour like Dean did. Cas could manage the mark. They were sure.

They fell into a cycle. They would hunt. They would go home. When things went wrong, Cas might break, a little. Use harsh words, or raise his voice. He would realize almost immediately what was happening, and to his credit, he knew how to shut it down and stop the outburst before it began. Then he would isolate himself until he felt he was ready to be around his family again. And then they would hunt again. And then they would go home again.

Then they heard about Claire. And Cas insisted he was fine to finish the hunt, and would mourn when they got home. And then he emptied the vampire nest more or less on his own, with his bare hands, and failed to realize he’d caught a human hostage in the crossfire until it was too late. It took them hours to shake Cas loose from his own mind and hold him up when he realized what he’d done. 

He isolated himself for almost two weeks, after that. It was the first time the rest of them realized that when Cas went off into the depths of the bunker on his own, he wasn’t just taking a breath to cool off. When the anger burned out, and Sam eventually found him, he was nothing but a hollow ruin of self-hatred and fear, curled up in the corner of a disused storeroom and losing his grip on the reality of physical existence.

“It’s getting worse,” he said. 

And then, the five words Sam had never wanted to hear again, that Dean would never forgive himself for letting so much as cross Cas’ mind.

“What about the Ma’lak box?”

Dean said no, outright. Sam and Eileen listened, carefully, as Castiel admitted that he was no longer fully in control, that the mark was claiming him as it had claimed Dean. He’d had chinks in his armour all along - they just only seemed to show from the inside.

They couldn’t release Chuck. There was no one else who could take the mark - even if Castiel would have let them. And so Cas made a very sound, educated choice about where he was to spend the rest of eternity, and Dean argued, and they didn’t speak for four days. When they did, Dean swung first, and was left numb and confused when Cas didn’t hit back.

He walked away. He came back an hour later and spoke softly, comforting Dean as if he was explaining to a young child and not a grown man who’d suffered loss before. In retrospect, of course, Dean knew why. When it was the last chance he had to make things right - and keep them that way - he wasn’t going to risk losing Dean now. Not now. Not after everything.

“You need to help me,” Cas said, in the quiet in the kitchen that night. Dean sat across from him, their clasped hands resting between them on the table. “I need you not to let me hurt you.”

“You leaving hurts me,” Dean said.

“I’ll have to leave sooner or later,” Cas said. “It’ll hurt less if I’m still me.”

Dean scoffed.

“Just make me a promise that when I can’t control myself, you’ll do it for me.”

He squeezed Dean’s hand. Dean squeezed back.

Within six weeks, not a shred of that self control was left, and he was forced into the box kicking and screaming.

~~~

Castiel had been locked up in the Ma’lak box for two days, six hours, and thirty seven minutes, and he had screamed ceaselessly for the first two days and three. 

Dean sat with his back to the cool metal, bottle in hand, eyes closed. His jaw still ached from where Cas had nearly shattered it in the fight to escape the inevitability of the box, and in spite of it all, Dean kind of felt like he deserved it. He hadn’t slept, for the ache. For the screaming. When he left the room, he just heard it in his head, instead. He wasn’t sure if the quiet was better or worse.

Eventually, weakly, the cracked voice came creeping out the few millimeters of space between the lid and the base. “Dean?”

Dean didn’t answer, terrified it would only start Cas going again.

“Are you still there?”

Dean took a deep breath. “Yeah, Cas,” he said. “I’m here.”

“Please,” Cas said. “Dean, please let me out.”

“You know I can’t do that.”

“I know what I said but I don’t want to be in here anymore, Dean, please.”

This was definitely worse than the screaming.

“I can’t.”

“He made me so I could suffer for his amusement,” Cas said. “He didn’t let me die. I can’t live forever alone with him inside me, Dean. I can’t. It’s so much worse than death, worse than the empty.”

“I’m sorry.”

“Would you come with me?” Cas asked. “Please?”

Dean found himself turning to side eye Cas through the barrier between them. “What?”

“I can keep you alive,” Cas said. “With two of us it would-- would be better. I just don’t want to be alone, Dean, please.”

“Cas--” Dean began.

“Please.”

“No.”

The Ma’lak box shook and rang with the force of Castiel pounding against the inside, pressing bruisingly hard against Dean’s back. He scrambled to his feet to put his hands and his weight on the lid, as if he needed to physically hold it shut, or as if it would calm the beast inside.

“Hey, calm down!” Dean barked.

“I died for you!” Castiel wailed. His voice was too broken from the last two days to hold any command, and it broke Dean’s heart. “I gave you everything! My whole life!”

“You asked for this, Cas! You said it was the only way!”

“It’s always the only way! And you always figure it out! If it were Sam, you’d have it figured out by now! Why did you give up?! Because I’m not useful enough anymore?! Because you’re happy to be rid of me?!”

“Would you shut the hell up?!” Dean demanded. “We haven’t given up, Cas. Why do you think you aren’t in the ground yet?”

Cas seemed to begrudgingly accept that excuse, and went silent. 

Eventually, he said “we could just be the four of us. You, and I, and Sam and Eileen.”

“Don’t think we’d all fit in there, buddy,” Dean said with a sigh, and anticipating no further violence, sat down on the lid.

“Cave in all the bunker’s entrances. I could keep three of you alive as easily as one.”

“Until you went crazy and killed us all,” Dean said, with deceptive gentleness.

Cas was quiet for a moment, seeming to consider it. “I could just bring you back,” he said.

“That’s horrific.”

“Every option on the plate is horrific,” Cas replied. “Stay trapped here and live for eons or die as the world burns. Whether we live together or die apart is the question.”

Dean had no answer. He wasn’t willing to talk about it, anymore. 

He left before Cas could ramble any further.

~~~

Dean was unrepentantly jealous that Cas seemed to behave for Sam, most of the time. They’d speak in subdued tones about the facts of life - how they all were, what was going on outside, reassurances of the absolute necessity of The Plan. Sam would clumsily interpret for Eileen, once in a while, when Cas was being very reasonable. Dean even caught Sam reading aloud to Cas, once, and he wasn’t sure why Sam seemed to be embarrassed about it.

The uselessness of it, maybe. The attempts to entertain Cas when he’d soon be in solitary with nothing but his own thoughts.

But when Dean arrived, Good Cas never lasted. He’d get worked up, fast, with fear or anger or despair. He’d beg for his freedom, or rail against the injustices of the world, and something about Dean made his emotions bubble to the surface until there was nothing for them to do but argue.

The more things change…

Dean caught Sam in the hallway, one night. His brother was leaning against the wall opposite the door, sniffling, tears in his eyes.

“What’s wrong?” Dean asked.

Sam shook his head. “Nothing,” he said. “Nothing. Just… Cas. He’s not really at home right now.”

“You know whatever he said, he doesn’t mean it.”

“He’s not angry, he’s just scared,” Sam said, and dried his eyes.

Dean heard the unspoken ‘therefore’ in Sam’s shaking breaths. Scared was worse.

Scared wasn’t the mark talking.

~~~

“Cas?” Dean asked, knocking gently on the lid of the box. “You lucid in there?”

There was an answering knock. So, more or less, Dean figured. He sat down beside the box on the floor, cradling his arm. He’d dislocated his shoulder three days ago, and it hurt like a bitch, but compared to the others he’d gotten off easy. He didn’t complain - not that Cas would care.

“How are you holding up?” Dean asked, knowing it was a dumb question. He’d been in there almost six weeks.

“Where did you go?” Cas asked, instead of answering.

“Montana,” Dean replied.

“How long were you gone?”

Dean swallowed. “Gone four days,” he said. “But it’s been six.”

“I see.”

“It was important. I’m sorry I didn’t come to talk to you right away,” Dean said. “Cas, things are starting to get pretty hairy out there.”

There was silence for a moment, before Cas asked, hesitantly, with a painful glimmer of hope in his voice, “do you need my help?”

“No,” Dean sighed. “It’s just… we’re still looking, Cas, but we’re starting to run up against hunts that are a bit more than your typical milk run, you know? Ten, fifteen bad guys, sometimes. Stronger than us. And every time we go out, now, we’re running a real risk that we might not come back.”

Castiel didn’t respond. Dean wondered if he knew what was coming or if he simply didn’t know what to say.

Dean continued. “We’re still looking, but if we don’t come back we need to make sure you’re secure,” he said. “We’ll know where you’re buried, when we find the answer. We’ll dig you back up.”

If they found an answer. If they survived that long.

Not that staring bleary-eyed at the pages of the same four books felt like it really counted as “still looking” anymore.

“You’re always fine. You always come back.”

“I can’t promise that, anymore,” Dean said, feeling every ounce of his exhaustion.

“Why can’t you just go in teams and leave someone here?” Cas asked.

“Eileen died, Cas,” Dean said. 

From inside, a soft, sad “oh.”

“That’s why I didn’t come see you right away. That’s why Sam is… Sam’s not coming. I don’t think.”

“... Not today, or…?”

“I don’t…” Dean sighed. He ran a hand over his face. “I don’t think I’m going to tell him.”

“So I won’t get to say goodbye,” Cas concluded.

“Yeah.”

“Do I get a choice?” Cas asked.

Dean shook his head. “He’s hurting, Cas,” he said. “He can’t… he can’t deal with this right now. Let him bury her, and I’ll… I’ll bury you.”

“Alive.”

Dean blinked.

“What?”

“I’m alive,” Cas said. “You’ll bury me alive.”

“Cas--”

“Why’s she so lucky?”

“Cas!”

“Let me out.”

He said it with such an even tone, Dean could almost have forgotten what they were talking about.

“No,” he said, when he’d overcome the shock.

“Let me out!” Cas shouted, and it was clear he was turning the corner into an episode. The lucidity never lasted long - he’d been lucky he’d gotten to speak to Cas at all.

“No.”

“If you weren’t so spineless you’d have killed me instead!” Cas wailed. He was banging his fists against the lid, now.

“I’m not having this conversation with you, Cas,” Dean said. His eyes stung. “God, I hate you for making me promise to do this.”

“You are not the one in this equation with a right to be hateful!”

Dean laid down on the ground, holding his arm at a careful angle, until he was on his good side with his forehead pressed against the hard steel, fingers brushing the runes he himself had carved.

“I’m too hurt to dig right now, but I’m gonna stay with you until I can do it, okay?” He asked.

“Don’t bother-- don’t fucking patronize me!”

“I love you.”

The final bang against the walls came seemingly just the other side of the metal from Dean’s forehead. It rattled his brains in his skull and made him feel dizzy. But it was the last one. After that, Cas lay quietly, though Dean could hear him heaving breath inside. Once or twice in the night, he thought he heard a sob.

~~~

His shoulder burned, but he kind of figured he deserved it.

Injured, and without Sam’s help, the digging took hours. With no controlled way to lower the Ma’lak box into the ground, he had to drop Cas in like something broken and unwanted. It made him wish he knew how to convince Cas that wasn’t the case.

It landed lid-side-down, and he could hear Cas turning over inside to adjust. Dean hopped down into the hole, standing on the box’s bottom, and crouched down.

“Can you hear me, Cas?” He asked.

“Dean,” was all Cas said.

Tentatively, Dean rapped his knuckles against the metal. “Can you find me?” He asked. He knocked again. “Find my hand.”

He knocked every few seconds until he heard an answering knock that emanated from the same spot.

“Now put your hand against it, okay?” Dean asked, placing his palm flat against the base. “That’s where I am. We’re touching, now. Are you doing it?”

“Yes.”

“We’re gonna come back for you.”

“I’m scared,” Cas said. His voice was so quiet, muffled by dirt and debris.

“I’m gonna come back for you,” Dean repeated. “I promise.”

Cas said nothing.

“I love you,” Dean said.

“I forgive you.”

It was the last thing Castiel ever said to another living thing.


End file.
